Vitamin supplementation and health outcomes
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Vitamin Supplementation and Health Outcomes: Evidence from Recent Research
Vitamin C Supplementation and Health Outcomes
Vitamin C intake has been linked to a reduced risk of all-cause mortality, cardiovascular disease, and several cancers, including oesophageal, gastric, cervical, and lung cancer. Additional benefits have been observed for respiratory, neurological, ophthalmologic, musculoskeletal, renal, and dental health. However, there are potential risks, such as an increased risk of breast cancer and kidney stones with vitamin C supplement use. Overall, the benefits of vitamin C intake appear to outweigh the disadvantages, but recommendations for supplementation should be made cautiously and more high-quality studies are needed to confirm these findings .
Vitamin D Supplementation: Mortality, Cardiovascular, and Mental Health Outcomes
Vitamin D supplementation is associated with a small reduction in all-cause mortality, especially in higher-quality studies, but does not significantly reduce cardiovascular morbidity or mortality. The evidence does not support a reduction in specific cardiovascular events such as myocardial infarction, stroke, or heart failure. For mental health, most studies do not show a positive effect of vitamin D supplementation on depression, mood, or overall mental well-being in healthy adults, and results are inconsistent for depression specifically. Some studies suggest that vitamin D supplementation may be more effective when combined with physical activity or when vitamin D is obtained from food sources rather than supplements 2357+2 MORE.
Calcium and Vitamin D Supplementation: Fractures, Cancer, and Mortality
Combined calcium and vitamin D supplementation does not significantly reduce the risk of hip fractures or colorectal cancer in postmenopausal women. There is also no effect on cardiovascular disease or all-cause mortality. Some exploratory analyses suggest a lower incidence of vertebral fractures and in situ breast cancers among supplement users, but these findings are not robust enough to change general recommendations 45.
Vitamin and Mineral Supplementation During Pregnancy
In low- and middle-income countries, multiple micronutrient (MMN) supplementation during pregnancy improves several birth outcomes, such as reducing preterm birth, small-for-gestational-age infants, and low birthweight, compared to iron-folic acid (IFA) supplementation alone. MMN supplementation also improves some child health outcomes, including reduced diarrhea incidence and improved vitamin A status. However, micronutrient supplementation has little to no effect on maternal, neonatal, perinatal, or infant mortality. Single micronutrient supplementation shows benefits for specific outcomes, such as calcium for pre-eclampsia, iron for maternal anemia, and vitamin D for preterm births, but these effects are limited and context-specific .
Vitamin A Supplementation in Preterm Infants
Oral vitamin A supplementation in preterm infants does not significantly affect the duration of mechanical ventilation, oxygen requirement, or the incidence of moderate-to-severe bronchopulmonary dysplasia. There may be a slight reduction in the duration of noninvasive respiratory support, but no significant impact on mortality or other short-term health outcomes has been observed .
General Conclusions on Vitamin Supplementation and Health
Across the general population, high-quality evidence for the benefits of vitamin supplementation in improving major health outcomes, especially cardiovascular health, is minimal to non-existent. Most benefits are seen in specific populations or for targeted outcomes, such as pregnant women in low-resource settings or individuals with documented deficiencies. For the general public, maintaining a healthy lifestyle with adequate nutrition from food sources remains the most effective approach for improving and maintaining health 359.
In summary, while certain vitamin supplements can provide health benefits in specific contexts or populations, routine supplementation in the general population does not consistently improve major health outcomes. Supplementation should be tailored to individual needs and deficiencies, and more robust research is needed to clarify the benefits and risks in broader populations.
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